Asahi Kogaku Kogyo Kabushiki Kaisha

Naoyuki Uno

Masahiro Kawasaki

Fumio Urano

Tetsuji Shono

Harumi Aoki

Hiroshi Kurei

Eiichi Tano

Katsuhiko Nomura

Masao Jyojiki

Katsuhiko Miyata

Kunio Mita

Chiharu Mori

An automatic focus detecting device for a camera adapted to be miniaturized and provided in the form of an integrated circuit. Two arrays of light receiving elements or sensors are disposed in two planes parallel to the surface of the film in the camera on either side of the image plane. The output signals from the sensors are processed in a disclosed electronic circuit to detect desired focus conditions such as front focus, proper focus and rear focus for automatically moving the photographing lens to the position of proper focus.

Camera focus detecting device

Full and minimum aperture information is transmitted to a camera body from an interchangeable lens by coding possible combinations of the two values into various discrete single values and transmitting the single value to a decoder in the camera body. For instance, a projection may be provided on the lens barrel having a height corresponding to a particular combination of full and minimum aperture values.

Lens barrel having an aperture information transmission section

An apparatus to be used in a camera to digitally indicate inside the viewfinder, film exposure values based upon iris opening, shutter speed and film exposure index.

Indicator device used in camera to indicate exposure values within a

An automatic exposure control circuit for a camera is disclosed. The circuit is capable of automatically controlling the shutter speed when the diaphragm is manually set, and is capable of automatically controlling the diaphragm opening when the shutter speed is manually set. In both cases the same transducer is used for the manual diaphragm or shutter speed selection.

Exposure control device

Very precise indications of the Apex indication values in a camera are displayed through the viewfinder. The nominal value is displayed numerically and further indications are provided to display fractional parts of one step of a nominal Apex indication value.

Digital indicator device for indicating photographing exposure values in

An automatic exposure control device is disclosed which is capable of aperture dominant and shutter speed dominant exposure control operation as well as manual exposure control operation. A logarithmic compression circuit including transducers develops voltages directly dependent upon the APEX indicating quantities Bv, Sv, Tv and Av. For automatic operation one of the voltages dependent upon Tv or Av is set into the circuit by manual control, and the other is calculated by the APEX indication formula Bv + Sv = Tv + Av, and applied as an output to the shutter control or aperture control mechanism. An indicator means is connected in the circuit to provide Tv or Av indications depending on the exposure control mode selected for the camera.

An automatic exposure control device for a single lens reflex camera characterized in that a stop determining member which stops down diaphragm blades by rotation thereof at a predetermined speed is released by a shutter release plate. A time constant circuit is started to operate simultaneously with the start of rotation of said stop determining member, and the rotation of said stop determining member is stopped by an electromagnetic mechanism when a time has lapsed. The length of said time linearly corresponds to the stop size determined by APEX operation based on the output voltage of said time constant circuit as an operation factor.

Automatic exposure control device for single lens reflex camera

A light meter for a SLR camera implements both initial exposure time display and automatic exposure time control using a single light sensing element 8. The reflex mirror 3is formed as a beam splitter or half-mirror. When lowered, some of the viewfinder light passes through the mirror and is reflected onto the sensing face of the element 8 by the shutter curtains 9 or 10 to enable the time display function. When the mirror is raised and the lens diaphragm 2 reduced, the light is again reflected from the curtains and/or film surface 11 onto the sensing element face to enable the time control function. A hinged shield 13 may be provided to block light from entering the camera box 12 via the rangefinder lens 7 when the mirror 3 is raised, and dual sensing elements 8, 8' may be employed together with an additional reflecting mirror 15 and an angled or concave shield 13 ' to effect a uniform vertical light distribution sensitivity in both the display and control modes.

Dual-mode light meter system for SLR camera using beam-splitting reflex

A light meter circuit for an SLR camera implements full aperture viewfinding with a preselected exposure time by providing an integrating capacitor 25 for controlling the exposure time, a first switch 24 for enabling the charging of the capacitor, circuit means 26, 29 for controlling the charging of the capacitor, a variable resistor 30 for establishing the lens aperture value in an exposure time display mode, a fixed resistor 31 for establishing the aperture value in an exposure time control mode, and a second switch 32 for connecting one of the resistors to an input of the charging control circuit. When the shutter release button is depressed the second switch is transferred from the variable to the fixed resistor, and the first switch is subsequently opened to enable the charging of the capacitor.

Dual function exposure time display and control circuit for SLR camera

An automatic iris adjustment control for cameras which, using the APEX operational equations, compares the brightness value Bv and film sensitivity value Sv with the iris size indication value Av and shutter speed value Tv. The iris size indicating value Av is derived from the sum of pulses created by a pulse generator which operates in conjunction with the moving adjustment of the iris size. When the values are compared and found equal, an electro-magnet is de-energized stopping the movement of the adjustable iris at the correct iris setting.

Automatic exposure control device in a camera

A shutter speed digital display device for cameras equipped with both automatic and manual shutter speed controls is disclosed. A shutter speed display control circuit generates a first digital signal in accordance with the adjustment of the camera's shutter speed by an automatic shutter speed control circuit. The first digital signal is decoded and used to control a light-transmitting liquid crystal device display. In addition, when the camera is in a manual mode of operation, the first digital signal is compared with a second digital signal related to manually adjusted shutter speed. If the comparisons are equal, a coincidence indicator is energized.

Shutter speed digital display device for cameras

A method and apparatus for automatic iris control of cameras having an exposure value indicator located within the camera's viewfinder. The indicator emits light such that a photosensor when moving over the indicator face, senses the light and through associated circuitry and mechanisms stops the movement of an adjusting iris.

Growing community of inventors

Urawa, Japan

Naoyuki Uno